1. Field of the Invention
This invention relates to vehicle wheel brake systems. More particularly, this invention relates to a caliper adapter for use in vehicle brake systems that include a disc brake assembly and a redundant drum brake assembly for providing a parking brake function.
2. Description of the Prior Art
In modern day vehicles, wheel brake assemblies are used that are conventionally known as disc brakes. Disc brakes are preferred for many applications for widely-known reasons. The use of disc brakes for rear wheels on a vehicle, however, introduces certain problems. For example, disc brakes are not ideal for use as a parking brake.
One problem associated with the use of disc brakes for a parking brake, includes a potential deformation of the rotor, which the brakes act upon. When disc brakes have been used for decelerating the rotation of the rear wheels of a vehicle, the disc brake pads typically become very hot. When these same pads are then used for a parking brake function, the pads are clamped about the rotor in a fixed position for a long period of time. The relatively large amount of heat on the disc brake pads has the potential of introducing deformities into the rotor, which can interfere with optimum function of the disc brakes in later braking applications.
Accordingly, it has been proposed to include a redundant drum brake assembly for vehicles that have disc brakes on the rear wheels. Such a configuration would include a "drum-in-hat" rotor assembly that has disc brakes acting on a disc portion of the rotor and a drum brake assembly acting on a rotor barrel or hat portion. The drum brakes, in such systems, are used solely for a parking brake function in order to avoid the potential difficulties introduced by using the disc brakes as discussed above.
The presence of a redundant drum brake assembly introduces additional parts and weight to the vehicle brake system. Moreover, the inclusion of the drum brake assembly introduces design challenges in that the brake assembly must be capable of supporting the disc brakes and the drum brakes such that each are functional as required by a particular application. In some instances, special caliper adapters have been used for mounting the disc brakes and for supporting the redundant drum brake assembly. Such adapters are functional, however, they introduce additional weight and, because of their size, are cumbersome and may not be readily adaptable to many vehicle wheel systems. Therefore, it is desirable to provide improved components for vehicle wheel brake systems that include a redundant drum brake for a parking brake feature.
This invention provides an improved caliper adapter that mountingly supports the disc brake assembly and redundant drum brake assembly in an effective manner while also providing space, weight and cost saving advantages.